The move comes amid a solid week of US officials warning Russia away from any involvement in Iraq, and threats to punish Iraq if they dared to accept any help from Russia, insisting Iraq had to choose between the two potential partners in the war.

It’s unclear, however, if this authorization is a direct violation of US demands, since it appears to be limited just to operations in the immediate area around the border. Given how much of ISIS territory in Iraq is along the Syria border, however, it may be a subtle distinction.

On Thursday the Russian air force bombed a bridge over the Euphrates River effectively cutting off routes used by ISIS to deliver supplies to Syria from Iraq.

The deputy chief of the General Staff of Russia stressed that the strike was delivered in a region that, according to the US military, was fully controlled by IS militants.